• 제목/요약/키워드: Ocean conditions

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A Study on Comparison and Analysis of Motion Sickness Inquiry with MSI Calculation for Training Ship Kaya (실습선 가야호의 멀미도 조사와 MSI 계산의 비교 분석에 관한 연구)

  • Han, Seung-Jae;Ha, Young-Rok;Kim, In-Chul
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.4
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    • pp.412-418
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    • 2014
  • In this paper, for better boarding performance and pleasant boarding sensitivity of the ship, comparison and analysis was performed of motion sickness questionnaire with MSI(Motion Sickness Incidence) calculation based on ship motion theory(Strip Method) due to sea condition, incident angle in main sail way, economic speed, and calculation position of the training ship Kaya of Pukyong National University. On theses works, the rougher sea conditions became, the higher total motion sickness rate was occurred. The weights of vertical acceleration and the rates of MSI were higher at the bridge and the accommodation, which were located farther from the center of gravity of the ship. And effects of the vertical acceleration of the ship were increased in rolling then in head sea. In comparison between motion sickness questionnaire with MSI calculation, when the vertical acceleration increased, the motion sickness rate increased. The location to increase vertical acceleration and the location to cause motion sickness were agreed.

A Study on the Installation of SCR System for Generator Diesel Engine of Existing Ship (기존 선박의 디젤발전기용 SCR 시스템 설치에 관한 연구)

  • Ryu, Younghyun;Kim, Hongryeol;Cho, Gyubaek;Kim, Hongsuk;Nam, Jeonggil
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.4
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    • pp.412-417
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    • 2015
  • The IMO MEPC has been increasingly strengthening the emission standard for marine environment protection. In particular, nitrogen oxide (NOx) emissions of all ocean-going ships built from 2016 will be required to comply with the Tier-III regulation. In this study, a vanadia based SCR (Selective Catalytic Reduction) system developed for ship application was installed on a diesel engine for power generation of the training ship T/S SAENURI in Mokpo National Maritime University. For the present study, the exhaust pipeline of the generator diesel engine was modified to fit the urea SCR system. This study investigated the NOx reduction performance according to the two kind of injection method of urea solution (40%): Auto mode through the PLC (Programable Logic Control) and Manual mode. We were able to find the ammonia slip conditions when in manual mode method. So, the optimal urea injection quantity can be controlled at each engine load (25, 35, 50%) condition. It was achieved 80% reduction on nitrogen oxide. Furthermore, we found that the NOx reduction performance was better with the load up-down (while down to 25% from 50%) than the load down-up (while up to 50% from 25%) test.

Hull Form Development of an AFRAMAX Tanker with a Composite Stern Frameline Concept (복합선미선형 개념에 의한 AFRAMAX형 유조선 선형의 개발)

  • Ho-Chung Kim;Chun-Ju Lee;Su-Hyung Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.28 no.2
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    • pp.1-11
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    • 1991
  • A hull form for an Aframax tanker whore form parameters cover the values of $C_B{\simeq}0.8,\;L/B{\simeq}5.5\;and\;B/d{\simeq}3.5$ has been developed by applying a composite stern frameline concept and its excellent performance has been evaluated through a series of model tests at the Korea Research Institute of Ships and Ocean Engineering. The tests showed that this concept was very much promising in the cases of wide breadth and shallow draught vessels and suitably applicable to the stern frameline shape. For the comparison, a hull form developed by Japanese 'H' yard has been selected and the performances of two hull forms were evaluated by model tests and theoretical calculations. The comparison shows that Daewoo hull form requires less effective power by 10% and less delevered power by 5-6% at both full load and ballast conditions. In addition, it is suggested that Hushes method can give better correlationthan Froude method because the full scale resistance extrapolated by Froude method would be very much optimistic in case of the hull form with very low value of form factor.

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Estimation of Inundation Damages of Urban area Around Haeundae Beach Induced by Super Storm Surge Using Airborne LiDAR Data (항공 LiDAR 자료를 이용한 슈퍼태풍 내습시 해운대 해수욕장 인근 도심지역 침수 피해 규모 추정)

  • Han, Jong-Gyu;Kim, Seong-Pil;Chang, Dong-Ho;Chang, Tae-Soo
    • Spatial Information Research
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    • v.17 no.3
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    • pp.341-350
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    • 2009
  • As the power and scale of typhoons are growing due to global warming and socioeconomic damages induced by super-typhoons are increasing, it is important to estimate inundation damages and to prepare proper adaptation plans against an attack of the super-typhoon. In this paper, we estimated the inundation damages of urban area around Haeundae beach induced by super-typhoons which follow the route of Typhoon Maemi with the conditions of Typhoon Vera (Ise Bay in Japan, 1959), Typhoon Durian (Philippine, 2006) and Hurricane Katrina (New Oleans in U.S.A, 2005). The coastal area around the Haeundae beach (Busan and Gyeongnam province) is expectedly damaged by severe storm surges. In this study we calculated the rise of sea level height after harmonizing the different datum levels of land and ocean and estimated the inundation depth, inundation area and the amount of building damages by using airborne LiDAR data and GIS spatial analysis techniques more accurately and quantitatively. As many researchers are predicting that super-typhoon of overwhelming power will occur around the Korean peninsula in the near future, the results of this study are expected to contribute to producing coastal inundation map and evacuation planning.

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A Basic Study on the VTS Operator's Minimum Safe Distance (VTS관제사의 최소안전거리에 관한 기초 연구)

  • Kim, Jong-Sung
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.19 no.5
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    • pp.476-482
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    • 2013
  • This study aims to enhance the effectivity of VTS(Vessel Traffic Service) control by investigating the minimum safe distance between vessel and vessel, vessel and land(obstacle) for the vessel's safe navigation within the VTS control area. In addition, to suggest basic data for the safe navigation, this study has done survey and analysis to each VTS center, and individual on the minimum safe distance to VTS operators of each ports of korea. Through ocean voyage by training ship, Singapore and Malacca strait's congested vessel traffic zone's control distance was compared and investigated the difference on safe distance by the different VTS operators. As a result, there was huge difference of minimum safe distance between the VTS operators belong to the same center. Over all, the port with gentle coastline, like donghae, the safe distance was wider than the other port. On the other hand, port with complex coastline and frequent entry and departure of the vessel, like mokpo, the safe distance was the shortest of all. Therefore, development of module suitable to port's natural conditions and traffic volume's necessity is required, for the operators affiliated to the same VTS center control according to formal method. Lastly, the full discussion by the expert group about establishment of standard control procedure in the future should be considered as well.

Behavior Analysis and Control of a Moored Training Ship in an Exclusive Wharf (전용부두 계류중인 실습선의 선체거동 해석 및 제어에 관한 연구)

  • Cho, Ik-Soon
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.2
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    • pp.139-145
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    • 2017
  • Recently, gusts, typhoon and tsunamis have been occurring more frequently around the world. In such an emergency situation, a moored vessel can be used to predict and analyze other vessel behavior, but if the mooring system is destroyed, marine casualties can occur. Therefore, it is necessary to determine quantitatively whether a vessel should be kept in the harbour or evacuate. In this study, moored ship safety in an exclusive wharf according to swell effects on motion and mooring load have been investigated using numerical simulations. The maximum tension exerted on mooring lines exceeded the Safety Working Load for intervals 12 and 15 seconds. The maximum bollard force also exceeded 35 tons (allowable force) in all evaluation cases. The surge motion criteria result for safe working conditions exceeded 3 meters more than the wave period 12 seconds with a wind speed of 25 knots. As a result, a risk rating matrix (risk category- very high risk, high risk and moderate risk) was developed with reference to major external forces such as wind force, wave height and wave periods to provide criteria for determining the control of capabilities of mooring systems to prevent accidents.

Comparison of Biomass Productivity of the Microalgae, Tetraselmis sp. KCTC12236BP, in Polyvinyl Chloride Marine Photobioreactor and High Density Polyethylene Marine Photobioreactor (폴리비닐클로라이드 해양광생물반응기와 고밀도 폴리에틸렌 해양광생물반응기에서 미세조류, Tetraselmis sp. KCTC12236BP의 생산성 비교)

  • Jung, Seung-Gyun;Kim, Su-Kwon;Bun, Moon-Sup;Cho, Yonghee;Shin, Dong-Woo;Kim, Z-Hun;Lim, Sang-Min;Lee, Choul-Gyun
    • Journal of Marine Bioscience and Biotechnology
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    • v.8 no.1
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    • pp.18-23
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    • 2016
  • It is important to design photobioreactor by cheap material for economical microalgal biomass production. In this study, two types of marine photobioreactors (MPBR), made by either polyvinyl chloride (MPBR-PVC) or high density poly ethylene (MPBR-HDPE), are used and performance of these were compared. Tetraselmis sp. KCTC 12236BP is a green marine alga that isolated from Ganghwa Island, Korea, and the strain was used for marine cultivations using MPBR-PVC and MPBR-HDPE. The cultivations were performed three times in the spring season of 2012 using MPBR-PVC and of 2013 using MPBR-HDPE in the coastal area of Young Heung Island. As the results, MPBR-PVC shows higher biomass productivities than MPBR-HDPE, due to its high light transmittance. In the cultivations using MPBR-PVC, the average sea water temperature was $11.5^{\circ}C$ during the first experiment and $16.5^{\circ}C$ during the second and third experiments. Average light intensities during three times for experiments were 407.5, 268.1 and $273.0{\mu}{\cdot}E{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. The maximum fresh cell weight and average biomass productivity were $1.2g{\cdot}L^{-1}$ and $0.12g{\cdot}L^{-1}{\cdot}day^{-1}$. These results showed that Tetraselmis sp. KCTC12236BP were adapted well with the environmental conditions from ocean, and grow in the MPBR-PVC and MPBR-HDPE.

The Comparison of Extraction Process for Enhancement of Immunomodulating Activities of Ulva pertusa kjellman (구멍갈파래의 면역활성 증진을 위한 추출방법 비교)

  • Han, Jae-Gun;Ha, Ji-Hye;Choi, Yeong-Beom;Go, Jeong-Lim;Kang, Do-Hyung;Lee, Hyeon-Yong
    • Korean Journal of Food Science and Technology
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    • v.41 no.4
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    • pp.380-385
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    • 2009
  • The purpose of this study was to investigate the immunomodulatory effect of Ulva pertusa kjellman extract after undergoing a low temperature and high-pressure extraction process. First, the extracts obtained under the extraction conditions of 150 MPa and $80^{\circ}C$showed a relatively high antioxidant activity, with 90% super oxide radical activity compared to the extracts from conventional extraction process with water at $100^{\circ}C$. This extract also improved the growth of both human immune B and T cells up to $14.5{\times}10^4$ cells/mL and $14.2{\times}10^4$ cells/mL compared to $9.1{\times}10^4$ cells/mL in adding the extracts from conventional processes. It was found that the extracts obtained at 100 MPa and $60^{\circ}C$ showed better activities in NK cell growth and NO production from macrophage as $11.8{\times}10^2$ cells/mL and 30.0 ${\mu}M$. Overall, the extracts from high pressure and low temperature extraction process had relatively higher immune activation activity, possibly because the low temperature and high pressure extraction process may have higher yields of active compounds and have less damage to useful ingredients from relatively weak marine natural resources, such as Ulva pertusa kjellmann than that from the conventional extraction system.

Energy Efficiency Evaluation of IT based Ship Energy Saving System-(1) : Ship Handling Simulator Test Results (IT 기반의 선박에너지절감시스템 성능평가 방법-(1) : 육상시험 수행 결과)

  • Yoo, Yun-Ja
    • Journal of Navigation and Port Research
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    • v.39 no.6
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    • pp.465-472
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    • 2015
  • SEEMP (Ship Energy Efficiency Management Plan) guidelines for a ship's GHG reduction include a machinery modification of hull, an installation of energy efficiency enhanced attachment in hardware methods. It is also possible to bring a ship energy efficiency improvement by fuel-efficient operations or in other software methods. Hardware modification or installation on ship can bring financial burdens to a ship company compared to its improvement expectation. On the other hand, Software based energy-saving technology can be applicable on various ship types, and it is also expected high efficiency of ship energy use compared to hardware based technology in perspective of the investment costs and efficiency. In this paper, it is described that the ship handling simulator based evaluation was carried out using representative ship model of bulk, container and VLCC. Simulation environments were separated into 6 conditions according to the sea-state and weather condition, and the operation results were compared with those before and after energy saving system applied The container ship showed the largest FOC save rate after energy saving system applied although the others also showed energy save rate after using the system.

A Study of DEM Generation in the Ganghwado Southern Intertidal Flat Using Waterline Method and InSAR (수륙경계선 방법과 위상간섭기법을 이용한 강화도 남단 갯벌의 DEM 생성 연구)

  • Lee, Yoon-Kyung;Ryu, Joo-Hyung;Hong, Sang-Hoon;Won, Joong-Sun;Yoo, Hong-Rhyong
    • Journal of Wetlands Research
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    • v.8 no.3
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    • pp.29-38
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    • 2006
  • Digital Elevation Model (DEM) of intertidal flat can be widely used not only for scientific fields, coastal management, fisheries, ocean safety, military, but also for understanding natural and artificial topographic changes of the tidal flat. In this study, we generated DEM of the Ganghwado southern intertidal flat, the largest tidal flat in the west coast of the Korean Peninsula, using waterline method and interferometric synthetic aperture radar (InSAR). Constructed DEM which applied waterline method to the Landsat-5 TM and Landsat-7 ETM+ images closely expresses overall topographic relief of tidal flat. We found that the accuracy was determined by the number of waterlines which reflect various tidal conditions. The application of InSAR to the ERS-1/2 and ENVISAT images showed that only ERS-1/2 tandem pairs successfully generated DEM in the part of northern Yeongjongdo, but construction of DEM in the other areas was difficult due to the low coherence caused by a lot of surface remnant waters. In the near future, Kompsat-2 will provide satellite images having multi-spectral and high spatial resolution within a relatively short period at different sea levels. Application of waterline method to these images will help us construct a high precision tidal flat DEM. Also, we should develop DEM generation method using single-pass microwave satellite images.

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